JP2014185926A - Guidance display system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a guidance display system capable of suppressing reduction in visibility of a preceding vehicle due to a guidance image when the guidance image is displayed by being overlapped on a front landscape image.SOLUTION: In a guidance display system, a guidance image for guiding own vehicle is formed, the guidance image is made to be displayed in a display device by being overlapped on a front landscape image or the front landscape of the own vehicle, and a display mode is made different in an overlapping area overlapped on the front vehicle in the guidance image, and a non-overlapping area not overlapped on the front vehicle in the guidance image.

Description

  The present invention relates to a guidance display system for displaying a guidance image for guiding a vehicle.

  In relation to the guidance display system as described above, for example, a technique described in Patent Document 1 below is already known. The technique described in Patent Document 1 is configured to display a strip-shaped guide image indicating a guide route on a display device so as to be superimposed on a front landscape image that is a landscape image in front of the host vehicle.

JP 2012-233904 A

In the technique of Patent Document 1, as described in paragraph 0079, FIG. 17 and FIG. 18, when a filled belt-shaped guide image is displayed so as to be superimposed on a road surface in a forward landscape image, the vehicle travels ahead. Since the visibility of the vehicle ahead is deteriorated, the guidance image is configured to be displayed over the road surface in the front landscape image.
However, it is possible to reduce the distance on the screen between the guidance image and the road surface related to the guidance route by displaying the guidance image in an area overlapping the road surface rather than displaying it over the road surface. In some cases, it becomes easier to intuitively recognize the correspondence between the route and the road related to the guidance route.

  In view of this, there is a need for a guidance display system that can suppress a decrease in the visibility of the front vehicle due to the guidance image when the guidance image is displayed superimposed on the front landscape image.

  The characteristic configuration of the guidance display system for guiding a vehicle for guiding a vehicle according to the present invention includes a guidance route acquisition unit that acquires a guidance route of the host vehicle, and a forward image that is a landscape image in front of the host vehicle. A landscape image acquisition unit that acquires a landscape image, a forward vehicle recognition unit that recognizes a forward vehicle that is another vehicle traveling in front of the host vehicle based on the forward landscape image, and for guiding the host vehicle A guide image generating unit that generates the guide image, and a display unit that displays the guide image on a display device so as to overlap the front landscape image or the landscape in front of the host vehicle. Is that the display mode is different between an overlapping area that overlaps the preceding vehicle in the guidance image and a non-overlapping area that does not overlap the preceding vehicle in the guidance image.

According to this characteristic configuration, different display modes suitable for the respective regions can be set depending on whether the overlapping region overlaps the preceding vehicle or the non-overlapping region not overlapping the preceding vehicle. Therefore, the display mode of the overlapping area can be set to a display mode that can suppress a decrease in the visibility of the preceding vehicle compared to the non-overlapping area.
Therefore, even if the guidance image is displayed so as to overlap the preceding vehicle, the guidance image can be displayed so as to be superimposed on the front scenery image or the scenery ahead of the host vehicle while suppressing a decrease in the visibility of the preceding vehicle.

  Here, it is preferable that the guide image generation unit changes a display mode of the guide image according to an inter-vehicle distance between the host vehicle and the preceding vehicle.

  According to this configuration, the driver can intuitively recognize the inter-vehicle distance by changing the display mode of the guidance image. In addition, the guidance image can be provided with a warning function when the inter-vehicle distance is reduced.

  Here, it is preferable that the induced image generation unit makes at least one of color and transparency different between the overlapping region and the non-overlapping region.

  According to this configuration, it is easy to ensure the integrity of the overlap region and the non-overlap region of the guide image, as compared with the case where the shapes of the overlap region and the non-overlap region are different. Therefore, it is possible to display the guidance image so as to overlap the front scenery image or the scenery in front of the host vehicle while effectively suppressing a decrease in the visibility of the preceding vehicle in the overlapping region.

  Here, it is preferable that the guidance image generation unit sets the transparency of the guidance image in the overlapping area higher than the transparency of the guidance image in the non-overlapping area.

  According to this configuration, since the transparency of the overlapping region is relatively high, it is easy to see the front vehicle through the guidance image, and it is possible to effectively suppress a decrease in the visibility of the front vehicle.

  Here, the guide image generation unit sets the overlapping area as an image formed by a hollow outline, and the non-overlapping area is subjected to an image or a pattern in which the area surrounded by the outline is filled. An image is preferable.

  According to this configuration, the inside of the contour line of the guidance image is made transparent in the overlapping region, so that the front vehicle can be seen from the inside of the contour line, the visibility of the front vehicle can be ensured, and the shape of the guidance image is defined by the contour line. The driver can recognize the guidance route. On the other hand, in the non-overlapping region, an image in which the inside of the outline of the guide image is filled or an image with a pattern is formed, so that the visibility of the guide image can be improved.

  Here, it is preferable that the display unit is arranged so that the guidance image is seen to overlap the road included in the front landscape image or the landscape ahead of the host vehicle.

  According to this configuration, since the guidance image and the road surface appear to overlap, it is easy for the driver to intuitively recognize the correspondence between the guidance route and the road related to the guidance route.

  The technical features of the guidance display system according to the present invention having the above-described configurations can also be applied to the guidance display method and the guidance display program. Therefore, the present invention also covers such methods and programs. It can be. Note that a storage medium such as a DVD-ROM or a flash memory in which the guide display program is stored can also be a target of the right.

  In this case, the characteristic configuration of the guide display method for displaying the guide image for guiding the vehicle includes a guide route acquisition step in which the arithmetic processing device acquires the guide route of the host vehicle, and a scenery in front of the host vehicle. A landscape image acquisition step of acquiring a forward landscape image as an image, a forward vehicle recognition step of recognizing a forward vehicle that is another vehicle traveling in front of the own vehicle based on the forward landscape image, and the own vehicle A guide image generating step for generating the guide image for guiding the vehicle, and a display step for displaying the guide image on a display device so as to overlap the front landscape image or the landscape in front of the host vehicle, In the induced image generation step, an overlapping area that overlaps the preceding vehicle in the induced image and a non-overlapping area that does not overlap the preceding vehicle in the induced image are represented by It lies in the fact that different aspects.

  In addition, the characteristic configuration of the guidance display program for causing the computer to execute a process of displaying a guidance image for guiding the vehicle includes a guidance route acquisition step for obtaining the guidance route of the host vehicle, and a scenery in front of the host vehicle. A landscape image acquisition step of acquiring a forward landscape image that is an image of the vehicle, a forward vehicle recognition step of recognizing a forward vehicle that is another vehicle traveling in front of the own vehicle based on the forward landscape image, A guidance image generation step of generating the guidance image for guiding the vehicle, and a display step of causing the display device to display the guidance image on the display device so as to overlap the front landscape image or the landscape in front of the host vehicle. And in the guide image generation step, an overlapping region overlapping the front vehicle in the guide image and the front vehicle in the guide image Do not overlap with the non-overlapping region lies in the fact that different display modes.

  Naturally, these guidance display methods and guidance display programs can also obtain the effects of the guidance display system described above, and can incorporate some additional techniques listed as examples of suitable configurations thereof. It is.

1 is a block diagram illustrating a schematic configuration of a guidance display system according to an embodiment of the present invention. It is a figure for demonstrating the image recognition process which determines a vanishing point based on a white line. It is a figure for demonstrating the production | generation of a guidance image when a guidance path | route is a straight line. It is a figure for demonstrating the production | generation of a guidance image in case a right turn or a left turn is included in a guidance route. It is a figure for demonstrating the production | generation of a guidance image when the driving | running | working lane of a guidance route changes. It is a figure for demonstrating the production | generation of a guidance image in case a guidance path | route curves. It is a figure which shows the simple model of the coordinate system which concerns on perspective projection. It is a figure for demonstrating the process which produces | generates the guidance image along a guidance path | route in the coordinate system of a road surface in order to make a perspective projection. It is a figure for demonstrating the determination of an overlapping area | region and a non-overlapping area | region. This is an example in the case where the guidance image is displayed superimposed on the front landscape image or the landscape in front of the host vehicle when the guidance route is a straight line. This is an example of a case where a guidance image is displayed superimposed on a front landscape image or a landscape in front of the host vehicle when the travel lane of the guidance route changes. It is a figure for demonstrating the process which determines an overlap area and a non-overlap area based on the distance between vehicles. It is a figure for demonstrating the process which determines the area | region where a front vehicle is included in a front scenery image. It is a figure for demonstrating the process which determines the area | region where a front vehicle is included in a front scenery image. It is a figure for demonstrating the process which determines an inter-vehicle distance based on the recognition result of the front vehicle in a front landscape image. It is a flowchart for demonstrating the process of the guidance display system which concerns on embodiment of this invention.

An embodiment of a guidance display system 1 according to the present invention will be described.
The guidance display system 1 is a system that displays a guidance image Gi for guiding a vehicle. As shown in FIG. 1, the guidance display system 1 includes functional units such as a guidance route acquisition unit 30, a landscape image acquisition unit 31, a guidance image generation unit 32, a display unit 33, and a forward vehicle recognition unit 34.

The guide route acquisition unit 30 acquires the guide route of the host vehicle. The landscape image acquisition unit 31 acquires a front landscape image that is an image of a landscape in front of the host vehicle. The forward vehicle recognition unit 34 recognizes a forward vehicle, which is another vehicle that is traveling ahead of the host vehicle, based on the forward landscape image. The guidance image generation unit 32 generates a guidance image Gi for guiding the host vehicle. The display unit 33 displays the guidance image Gi on the display device 45 so as to overlap the front landscape image or the landscape in front of the host vehicle.
In such a configuration, the guide image generation unit 32 is characterized in that the display mode is different between an overlap region that overlaps the preceding vehicle in the guide image Gi and a non-overlap region that does not overlap the preceding vehicle in the guide image Gi. doing.
Hereinafter, the guidance display system 1 according to the present embodiment will be described in detail.

1. Guidance display system 1
The guidance display system 1 displays a guidance image Gi for guiding the vehicle.
The guidance display system 1 includes an arithmetic processing device such as one or a plurality of CPUs as a core member, and a RAM (random access memory) configured to be able to read and write data from the arithmetic processing device, A ROM (read-only memory) configured to be able to read data from a processing device, and a storage device such as a flash memory and a hard disk configured to be able to store and read a large amount of data. Yes. Each function unit 30 to 34 of the guidance display system 1 is configured by software (program) stored in the ROM or the like of the guidance display system 1 or hardware such as a separately provided arithmetic circuit, or both. ing. A guidance display program for causing the arithmetic processing unit to realize functions such as the functional units 30 to 34 is stored in a storage device such as a RAM or a ROM that can be referred to by the arithmetic processing unit.

In the present embodiment, the guidance display system 1 is incorporated in the information terminal device 2. Typically, a guidance display program is installed in the storage device of the information terminal device 2 to configure the guidance display system 1.
For example, the guidance display system 1 includes a navigation device mounted on a vehicle, an AV (sound / video) device for television, moving image reproduction, music reproduction, an information terminal device, and a multifunctional portable device that can be carried by a user. It is incorporated into telephones and portable information terminal devices. Alternatively, the guidance display system 1 may be incorporated in an information terminal device dedicated to the guidance display system 1.

  The guidance display program is stored in a storage medium such as a DVD-ROM or a flash memory and distributed to the user, or is distributed from the network server to the user via a communication network. The distributed or distributed guidance display program is stored in the storage device of the information terminal device 2.

  As shown in FIG. 1, the guidance display system 1 according to the present embodiment includes functional sections such as a guidance route acquisition unit 30, a landscape image acquisition unit 31, a guidance image generation unit 32, a display unit 33, and a forward vehicle recognition unit 34. It has. Hereinafter, each functional unit will be described in detail.

2. Guide route acquisition unit 30
The guide route acquisition unit 30 is a functional unit that performs processing for acquiring the guide route of the host vehicle.
In the present embodiment, the guidance route acquisition unit 30 is configured to acquire the guidance route searched by the guidance route search unit 40.
2-1. Guide route search unit 40
The guidance route search unit 40 is a functional unit that searches for a guidance route from the current position of the host vehicle to the target point. In the present embodiment, the guidance route search unit 40 is provided in the information terminal device 2 in which the guidance display system 1 is incorporated.
In the present embodiment, the guide route search unit 40 is configured to search for a guide route from the current position of the host vehicle to the target point using map data acquired from the map database 43. Note that various known methods such as the Dijkstra method can be used for the search for the guidance route.

  The map data to be acquired includes node data indicating points such as intersections on the map, road network data composed of link data indicating roads connecting the nodes, and the like. Each node data includes data such as location coordinates, location attributes, location names, etc., and each link data includes location coordinates and link lengths, road widths, road attributes, and passages of link start and end points. Data such as various vehicle types.

  In the present embodiment, the map database 43 is stored in the storage device of the information terminal device 2. Alternatively, the map database 43 is stored in an external information terminal device, and the guidance route search unit 40 is externally connected via data communication such as wireless communication or wired communication by a communication device provided in the information terminal device 2. The map data may be acquired from the information terminal device.

2-2. Own vehicle position acquisition unit 41
The own vehicle position acquisition unit 41 is a functional unit that performs a process of acquiring the current position of the own vehicle.
In the present embodiment, the host vehicle position acquisition unit 41 is configured to determine the current position (coordinates) of the host vehicle based on the position related information of the host vehicle acquired from the position information detection device 42. The position information detection device 42 includes a GPS (Global Positioning System) receiver, an acceleration sensor, an orientation sensor, a receiver that receives radio waves and light including point position information transmitted from a beacon installed on a road, and the like. Various devices for detecting position information are provided. The own vehicle position acquisition unit 41 is a communication device provided in the information terminal device 2 for radio waves including point position information such as base stations transmitted from a base station of a mobile phone line or an access point of a wireless LAN. It may be configured to receive and determine the current position of the host vehicle.

  Map data may be used for position determination. For example, the host vehicle position acquisition unit 41 performs the current matching of the host vehicle by pattern matching (so-called map matching) between the road network included in the map data and the route indicated by the position information history obtained from the position information detection device 42. It is configured to determine the position. In the present embodiment, the own vehicle position acquisition unit 41 and the position information detection device 42 are provided in the information terminal device 2 in which the guidance display system 1 is incorporated.

3. Landscape image acquisition unit 31
The landscape image acquisition unit 31 is a functional unit that performs a process of acquiring a front landscape image that is an image of a landscape in front of the host vehicle.
In the present embodiment, the landscape image acquisition unit 31 is configured to acquire a forward landscape image captured by the camera 44.

3-1. Camera 44
The camera 44 is attached so as to photograph a landscape in front of the host vehicle. The camera 44 is attached to the front side of the vehicle, for example, on the upper side of the dashboard or the rear side of the rearview mirror. When a head mounted display is used for the display device 45, a camera 44 provided in the head mounted display may be used.

4). Display unit 33
As shown in FIGS. 10 and 11, the display unit 33 is a functional unit that causes the display device 45 to display the guidance image Gi so as to overlap the front landscape image or the landscape in front of the host vehicle.
As the display device 45, a normal display such as a liquid crystal display, a head-up display, a head-mounted display, or the like is used.

<Normal display>
A normal display is a display such as a liquid crystal display in which the scenery behind the scene cannot be seen through. The normal display is fixed to the dashboard or the front panel so that the driver can see the display surface.
When a normal display is used for the display device 45, the display unit 33 displays the guide image Gi on the front landscape image captured by the camera 44 and displays it on the display.

<Head-up display>
The head-up display is realized by a method of projecting an image displayed on a liquid crystal display or the like onto a transparent optical glass element. The head-up display is transparent where no image is displayed, and the scenery behind the head-up display can be seen through. The head-up display is fixed to the indoor side of the windshield.

When a head-up display is used for the display device 45, the display unit 33 displays the guidance image Gi on the display so that the guidance image Gi overlaps the scenery in front of the host vehicle viewed through the windshield by the driver.
The display unit 33 uses information on the position and range of the landscape area in front of the host vehicle or the display area of the head-up display that the driver sees through the head-up display in the forward landscape image captured by the camera 44. The guide image Gi is displayed at an appropriate position in the display area of the display so that the guide image Gi overlaps the scenery in front of the host vehicle at an appropriate position.
When the camera 44 is provided as a module at a predetermined position and angle with respect to the display area of the head-up display, the information on the front landscape area or the position and range is stored in the guidance display system 1 in advance. It may be configured to be. Alternatively, the guidance display system 1 may be configured to store the information of the front landscape area or the position and range information by using a user interface interface.

<Head mounted display>
The head-mounted display is a display device that is worn on the driver's head and is of an optically transmissive type. The head mounted display is realized by a method of projecting an image displayed on a liquid crystal display or the like on a half mirror. The head-mounted display is transparent when no image is displayed, and the scenery behind the display can be seen through.

When a head mounted display is used for the display device 45, the display unit 33 displays the guide image Gi on the display so that the guide image Gi overlaps the scenery in front of the host vehicle included in the driver's field of view.
The head mounted display may be provided with a camera 44 that captures an image corresponding to the driver's field of view. In this case, the display unit 33 displays the position and range of the landscape area in front of the host vehicle or the display area of the head mounted display that the driver sees through the head mounted display in the forward landscape image captured by the camera 44. Using the information, the guide image Gi is displayed at an appropriate position in the display area of the display so that the guide image Gi overlaps the scenery ahead of the host vehicle at an appropriate position. In this case, the camera 44 is provided as a module at a predetermined position and angle with respect to the display area of the head mounted display, and the information on the front landscape area or the position and range is stored in the guidance display system 1. It is configured to be stored in advance.

  In addition, the head-mounted display is equipped with a gyro sensor, an acceleration sensor, and the like, and is configured to be able to determine the angle (tilt angle, pan angle, roll angle) of the driver's line-of-sight direction with respect to the straight forward direction of the host vehicle. May be. Based on the angle of the line-of-sight direction, the display unit 33 displays, in the forward landscape image taken by the camera 44, the landscape area in front of the host vehicle viewed through the head-mounted display or the display area of the head-mounted display. It may be configured to determine the position and range. Then, the display unit 33 uses the information on the determined landscape area or position and range in front of the display to display the appropriate display area of the display so that the guide image Gi overlaps the landscape in front of the host vehicle at an appropriate position. The guide image Gi is displayed at a proper position.

5. Guide image generator 32
The guidance image generation unit 32 is a functional unit that performs a process of generating a guidance image Gi for guiding the host vehicle to be displayed so as to be superimposed on the front scenery image or the scenery in front of the host vehicle. The guide image generation unit 32 includes an overlapping part display change unit 35 and a distance correspondence display change unit 36.

  The guide image generation unit 32 is configured to generate, as the guide image Gi, a band-like image extending along the guide route, an arrow-like image indicating the traveling direction along the guide route, and the like. In the present embodiment, the guide image generation unit 32 is described as an example in which an arrow-like image is generated as the guide image Gi.

The guide image generation unit 32 changes the shape of the guide image Gi based on the shape of the guide route ahead of the host vehicle. The guide image generation unit 32 generates a guide image Gi that represents the shape of the guide route within a predetermined distance range (for example, within a 500 m range) ahead of the host vehicle.
For example, when the guidance route within a predetermined distance range in front of the host vehicle is a straight line, the guidance image generation unit 32 is displayed as superimposed on the front scenery image or the scenery in front of the host vehicle as shown in FIG. Then, a guide image Gi is generated in which the belt-like portion extends straight toward the front of the host vehicle. When the guide image Gi is an arrow image, an arrowhead portion is provided at the tip of the belt-like portion.

Alternatively, when the guidance route within the predetermined distance range in front of the host vehicle includes a right turn or a left turn, the guidance image generation unit 32 displays the image on the front landscape image or the landscape in front of the host vehicle. As shown in FIG. 4, after extending the belt-shaped portion in the traveling direction of the host vehicle, a guidance image Gi that is bent and extended right or left with respect to the traveling direction of the host vehicle is generated.
Further, when the travel lane of the guidance route changes, the guidance image generation unit 32 extends the belt-shaped portion in the traveling direction of the host vehicle and then moves the strip-shaped portion with respect to the traveling direction of the host vehicle, as shown in FIG. Then, a guidance image Gi is generated in which the belt-like portion is bent and extended in the traveling direction of the host vehicle.
When the guide route curves, the guide image generation unit 32 generates a guide image Gi that bends and extends the belt-shaped portion in accordance with the shape of the guide route with respect to the traveling direction of the host vehicle, as shown in FIG. .
At this time, as shown in FIG. 3 to FIG. 6, the width of the belt-shaped portion may be reduced as it goes in the traveling direction.

In the present embodiment, the guide image generation unit 32 is configured to arrange the guide image Gi so as to overlap the road included in the front landscape image or the road ahead of the host vehicle. In the present embodiment, the guide image generation unit 32 is configured to arrange the guide image Gi in a lower area of the front landscape image or the landscape in front of the host vehicle where the road exists. The guide image generation unit 32 performs image recognition processing such as edge detection and color detection on the front landscape image to determine an area where a road exists.
The guide image generation unit 32 generates a guide image Gi that represents the shape of the guide route when displayed on the road. The guide image generation unit 32 generates a guide image Gi that extends from the lower side to the upper side in a region where a road exists in the front scenery image or the scenery in front of the host vehicle. Thereby, it becomes the guidance image Gi extended toward the advancing direction front from the side near the own vehicle.

  In the present embodiment, the guide image generation unit 32 is configured to generate a guide image Gi having a sense of depth along the guide route. Specifically, the guidance image generation unit 32 generates a guidance image Gi that extends along the road surface of the guidance route when displayed superimposed on the front scenery image or the scenery in front of the host vehicle, The width of the guide image Gi is decreased as it goes in the traveling direction.

<Guiding image Gi generation based on vanishing point>
The guide image generation unit 32 generates a guide image Gi that extends from the front edge portion of the host vehicle toward the vanishing point of the traveling road when displayed on the front landscape image or the scene in front of the host vehicle. It may be configured to.
The positional relationship of the image coordinate system of the camera 44 with respect to the coordinate system in the straight ahead direction of the host vehicle along the traveling road surface changes depending on the mounting position and mounting angle of the camera 44. Specifically, depending on the mounting position and angle of the camera 44, the height of the focal position of the camera 44 with respect to the road surface, the tilt angle of the focal direction of the camera 44 (the central axis of the camera field of view) with respect to the forward straight direction of the host vehicle, pan The amount of offset of the focal position of the camera 44 with respect to an angle, a roll angle, or the like, or the straight forward direction of the host vehicle changes. The position of the vanishing point of the front road of the host vehicle and the position of the front edge of the host vehicle in the front landscape image in the front landscape image taken by the camera 44 change depending on the mounting position and angle of the camera 44. It is desirable to determine these positions and generate the guidance image Gi according to the position of the vanishing point or the position of the front edge of the host vehicle.

  As shown in FIG. 2, the guide image generating unit 32 performs image recognition processing on the forward landscape image captured by the camera 44 to recognize white lines on both the left and right sides of the traveling lane, and the white lines on both the left and right sides intersect at the front. The point is determined to be the vanishing point Pd. The guide image generation unit 32 performs, for example, image recognition processing such as edge detection and Hough transform on the front landscape image to detect white lines on the left and right sides of the traveling lane. Further, for example, the guide image generation unit 32 linearly approximates the left white line and the right white line, and determines the position of the intersection of the left approximate line and the right approximate line as the position of the vanishing point Pd. The vanishing point Pd determined in this way corresponds to the vanishing point Pd when the road ahead is a straight line. Note that in the forward landscape image, the ratio of the white line immediately ahead of the host vehicle is high, and the road immediately ahead of the host vehicle is substantially straight, which corresponds to straight line approximation when the front road is a straight line. The guide image generation unit 32 may be configured to perform statistical processing on the determined position of the vanishing point Pd and determine, for example, a position with high frequency as the final position of the vanishing point Pd.

  In addition, the guide image generation unit 32 determines the center line of the left approximate line and the right approximate line as the straight forward direction of the host vehicle along the road surface. The guide image generation unit 32 may be configured to perform statistical processing on the determined center line, and determine, for example, a straight line obtained by averaging processing as the final forward straight direction. Here, the forward straight traveling direction is a direction of an axis that extends in the forward straight traveling direction of the host vehicle along the traveling road surface through the center of the lateral width of the host vehicle.

  The guide image generation unit 32 performs image recognition processing such as edge detection on the front landscape image, and determines the position of the front edge portion of the host vehicle photographed in the front landscape image. For example, the guidance image generation unit 32 determines a region with little edge change or the like in the lower region of the front landscape image, and determines the position of the upper end of the determined region as the position of the front edge of the host vehicle. If it is not possible to determine a region with little edge change, the guide image generation unit 32 determines that the front edge of the host vehicle is not captured in the front landscape image, and sets the position of the lower end of the front landscape image in front of the host vehicle. The edge position is determined. The guide image generation unit 32 determines the intersection of the forward straight direction and the front edge as the center point Pc of the front edge.

The guide image generation unit 32 is configured to generate the guide image Gi based on the vanishing point Pd and the center point Pc of the leading edge. Specifically, the guidance image generation unit 32 is configured to generate a guidance image Gi that extends from the center point Pc of the front edge toward the vanishing point Pd of the traveling road.
When the guide route is a straight road along the straight forward direction, the guide image generating unit 32, as shown in FIG. 3, guide image Gi extending in a belt shape from the center point Pc of the front edge to the vanishing point Pd of the traveling road. Is generated.
The lateral width of the belt-shaped portion is decreased as it goes from the center point Pc of the front edge portion toward the forward straight direction (the vanishing point Pd). For example, the left boundary line of the belt-like portion extends straight from a point on the left side by a predetermined distance from the center point Pc of the front edge portion toward the vanishing point Pd, and the right boundary line of the belt-like portion is the center point of the front edge portion. It is generated so as to extend straight from a point on the right side by a predetermined distance from Pc toward the vanishing point Pd. And the guidance image generation part 32 produces | generates an arrowhead part at the front-end | tip of the strip | belt-shaped part which goes to the vanishing point Pd, when the guidance image Gi is made into the arrow image. The guide image generation unit 32 is configured to generate only the outline of the guide image Gi at this stage. When the guide image Gi is a band-shaped image, an arrowhead portion is not generated and the image is only a band-shaped portion.

When the guidance route turns right or left in front, the guide image generation unit 32 extends the strip portion from the center point Pc of the front edge portion toward the vanishing point Pd as shown in FIG. In the position Td corresponding to the right turn or the left turn, it is configured to bend and extend to the right side or the left side at an angle corresponding to the right turn or the left turn road. And the arrowhead part is produced | generated at the front-end | tip of the strip | belt-shaped part bent to the right side or the left side.
Based on the distance Tz to the right / left turn position and the length Hd between the front edge center point Pc and the vanishing point Pd, the guide image generation unit 32 uses a calculation formula as shown below, A position Td corresponding to a right turn or a left turn in the image can be determined.
Td = Hd (1-Fd / Tz) (1)
Here, the right / left turn position Td is a length along the forward straight direction from the center point Pc of the front edge in the forward landscape image. Hd is the length between the front edge center point Pc and the vanishing point Pd in the front landscape image. Fd is the focal length of the camera 44. Tz is the distance from the vehicle position to the left / right turn position in the actual guidance route. The focal length of the camera 44 is stored in advance in the guidance display system 1 or set by the user.

  When the travel lane of the guidance route changes, the guide image generation unit 32 extends the belt-shaped portion from the center point Pc of the front edge toward the vanishing point Pd as shown in FIG. It is configured to bend rightward or leftward at the changing position and extend to the center position of the lateral width of the changed travel lane, and then bend toward the vanishing point Pd and extend to the vanishing point Pd.

  When the guide route is curved, as shown in FIG. 6, the guide image generation unit 32 changes the band-like portion from the center point Pc of the front edge portion from the vanishing point Pd according to the shape of the guide route. Up to a length corresponding to the shape of the guide path.

<Perspective projection>
The guide image generation unit 32 generates a guide image Gi by perspectively projecting the guide image Gio drawn along the guide route on the screen corresponding to the front landscape image or the front landscape of the host vehicle in the coordinate system of the road surface. It may be configured to.

FIG. 7 shows a simple model of a coordinate system related to perspective projection.
The coordinate system of the road surface is such that the forward straight direction of the host vehicle along the road surface is the z-axis, the lateral direction perpendicular to the z-axis and toward the right side of the host vehicle is the x-axis, and the road surface ( The upward direction that is orthogonal to the z-axis and the y-axis and toward the upper side of the host vehicle is the y-axis. The coordinate system is set in a simplified manner so that the coordinate position (x, y, z) of the focal position Pf (viewpoint position) in the road surface coordinate system becomes (0, H, 0).

  The front landscape image or the coordinate system of the landscape in front of the host vehicle (referred to as the image coordinate system) is an xg axis parallel to the lateral direction of the front landscape image or the landscape in front of the host vehicle toward the right, The yg axis is parallel to the vertical direction of the landscape in front of the vehicle and is directed upward. The image coordinate system is set at a position separated from the focal position Pf (viewpoint position) by a focal distance Fd. The xg axis is parallel to the x axis, the yg axis is parallel to the y axis, and the origin (xg, yg) = (0, 0) of the image coordinate system is the coordinate position ( The coordinate system is set in a simplified manner so that x, y, z) = (0, 0, Fd).

The perspective projection from the coordinate position (X, 0, Z) of the road surface in the coordinate system (x, y, z) of the road surface to the coordinate position (Xg, Yg) in the coordinate system (xg, yg) of the screen is as follows. It becomes like the formula.
(Xg, Yg) = (X / Z × Fd, H (1-Fd / Z)) (2)
Conversely, reverse perspective from the coordinate position (Xg, Yg) in the coordinate system (xg, yg) of the screen to the coordinate position (X, 0, Z) of the road surface in the coordinate system (x, y, z) of the road surface. The projection is as follows:
(X, 0, Z) = (H / (H−Yg) × Xg, 0, H / (H−Yg) × Fd)
... (3)

The position of the vanishing point Pd in the front scenery image or the scenery in front of the host vehicle is the intersection of the straight line extending in parallel with the z axis from the focal position Pf (viewpoint position) and the front scenery image or the scenery in front of the host vehicle. Become. In Expression (2), when the value of Z is infinite, the position of the vanishing point Pd is as shown in the following expression.
(Xg, Yg) = (0, H) (4)

  Based on the position information of the guide route, the vehicle position information, the angle of the straight forward direction with respect to the direction, etc., the guide image generating unit 32, as shown in FIG. 8, the road surface (x, 0, In z), a guide image Gio along the guide path is generated. More specifically, the guidance image generation unit 32 determines the road surface (x, 0, z) in the coordinate system of the road surface based on the position information of the guidance route, the vehicle position information, the angle of the straight forward direction with respect to the direction, and the like. ) To obtain the coordinate position of the guide route. Then, the guide image generation unit 32 determines the coordinate position (X, 0, Z) of the guide image along the guide route on the road surface (x, 0, z) of the road surface coordinate system. Then, the guide image generation unit 32 uses the perspective projection conversion formula and the conversion coefficient as shown in Formula (2), and based on the coordinate position (X, 0, Z) of the guide image, the coordinate position (Xg, Yg) is calculated, and a guide image Gi as shown in FIG. 4 is generated.

  At this time, the guidance image generation unit 32 may be configured to reflect a change in the perspective projection conversion coefficient caused by variations in the mounting position and mounting angle of the camera 44. The change in the perspective projection conversion coefficient can be obtained based on the white line detected by performing the image recognition process on the front landscape image as described above. For example, when the straight white approximate line of the left white line and the straight white approximate line of the right white line in the forward landscape image described with reference to FIG. 2 are reverse-perspectively projected onto the road surface of the road surface coordinate system, the reverse perspective projection is performed. A perspective projection conversion coefficient is obtained so that the straight line approximation line of the left white line and the straight line approximation line of the right white line are parallel around the straight forward direction (z axis).

  When a head-mounted display is used for the display device 45, based on the angle of the driver's line-of-sight direction with respect to the forward straight direction, from the coordinate position of the road surface in the road surface coordinate system, It may be configured to obtain a perspective projection conversion coefficient to the coordinate system of the screen related to the display area of the head mounted display, and generate the guidance image Gi by performing the perspective projection as described above.

5-1. Duplicate portion display change unit 35
As shown in FIGS. 10 to 12, the overlapping part display changing unit 35 displays the display mode between the overlapping area Ao that overlaps the preceding vehicle in the guidance image Gi and the non-overlapping area Ano that does not overlap the preceding vehicle in the guidance image Gi. It is configured to be different. Even if the guidance image Gi overlaps with the preceding vehicle, the display mode is made different between the overlapping area Ao and the non-overlapping area Ano so that the visibility of the preceding vehicle does not deteriorate.

The overlapping part display changing unit 35 displays an overlapping area Ao that overlaps the front vehicle in the guidance image Gi and the front vehicle in the guidance image Gi when the guidance image Gi is displayed superimposed on the front scenery image or the scenery in front of the host vehicle. The non-overlapping area Ano that does not overlap with the other is determined.
In the present embodiment, as shown in FIG. 9, the overlapping part display changing unit 35 determines that the area of the guidance image Gi that overlaps the area Ac of the forward vehicle recognized by the forward vehicle recognizing part 34 described later as the overlapping area Ao, A region of the guidance image Gi that does not overlap with the region of the preceding vehicle is determined as a non-overlapping region Ano.

  The display modes that are different between the overlapping region Ao and the non-overlapping region Ano include color (color tone, lightness), transparency, pattern, shape, change mode (flashing frequency, etc.), and the like. In the present embodiment, the overlapping part display changing unit 35 changes at least one of color and transparency between the overlapping area Ao and the non-overlapping area Ano.

For example, the overlapping part display changing unit 35 may be configured to make the transparency of the guidance image Gi in the overlapping area Ao higher than the transparency of the guidance image Gi in the non-overlapping area Ano. Since the overlapping area Ao has higher transparency, it becomes easier to see through the vehicle for the front vehicle, and a decrease in the visibility of the vehicle ahead can be suppressed.
As shown in FIG. 10, the overlapping part display changing unit 35 sets the overlapping area Ao as an image formed with a hollow outline, and sets the non-overlapping area Ano as an image in which the area surrounded by the outline is filled or An image with a pattern may be used.
The hollow portion in the overlap area Ao is transparent, and the vehicle ahead can be seen through. The filled portion in the non-overlapping area Ano may be filled with transparency so that the scenery can be seen through to some extent. In addition, the patterned portion in the non-overlapping area Ano may be a repeated pattern such as a hatched pattern or a dot pattern so that the scenery can be seen through to some extent.

  The overlapping part display changing unit 35 may be configured to make the outline of the guidance image Gi in the overlapping area Ao thinner than the outline of the guidance image Gi in the non-overlapping area Ano. Further, the overlapping part display changing unit 35 may be configured to make the blinking frequency of the guidance image Gi in the overlapping area Ao higher than the blinking frequency of the guidance image Gi in the non-overlapping area Ano. The overlapping part display changing unit 35 may be configured to make the color tone of the guidance image Gi in the overlapping area Ao lighter than the color tone of the guidance image Gi in the non-overlapping area Ano.

  When the guidance image Gi protrudes from the current travel lane, as shown in the guidance image Gi for changing the travel lane shown in FIG. The overlapping area is also determined as the overlapping area Ao, and the display mode is changed. Moreover, the overlapping part display changing unit 35 may determine that the area overlapping the oncoming vehicle or the stopped vehicle traveling in the oncoming lane as the overlapping area Ao and change the display mode.

<Area determination based on distance between vehicles>
The overlapping part display changing unit 35 may be configured to determine the overlapping area Ao and the non-overlapping area Ano based on the inter-vehicle distance between the host vehicle and the preceding vehicle determined by the inter-vehicle distance determining unit 37.
Based on the inter-vehicle distance Cz and the length Hd between the leading edge center point Pc and the vanishing point Pd, the overlapping part display changing unit 35 calculates a calculation formula as shown in the following formula similar to the formula (1). It is possible to determine the position Cd of the lower end portion of the forward vehicle in the forward landscape image.
Cd = Hd (1-Fd / Cz) (5)
Here, as shown in FIG. 12, the position Cd of the lower end portion of the forward vehicle is the position of the lower end portion of the forward vehicle in the forward landscape image, and the center point Pc of the front edge portion along the forward straight direction and the forward vehicle. It is the length between the lower end part of. Hd is a length between the front edge center point Pc and the vanishing point Pd in the front landscape image. Fd is the focal length of the camera 44. Cz is the inter-vehicle distance between the host vehicle and the preceding vehicle on the actual traveling road.

  As illustrated in FIG. 12, the overlapping portion display changing unit 35 determines that the region of the guidance image Gi that overlaps the upper region with respect to the horizontal line passing through the position Cd at the lower end of the preceding vehicle is the overlapping region Ao in the front landscape image. The region of the guide image Gi that overlaps the region below the horizontal line passing through the position Cd of the lower end portion of the preceding vehicle is determined as the non-overlapping region Ano.

5-2. Distance correspondence display change unit 36
The distance correspondence display changing unit 36 is configured to change the display mode of the guidance image Gi according to the inter-vehicle distance between the host vehicle and the preceding vehicle determined by the inter-vehicle distance determining unit 37.
The display mode that varies depending on the inter-vehicle distance includes the color (color tone, brightness), transparency, pattern, shape, mode of change (flashing, etc.), and the like, similar to the overlapping portion display change unit 35. By changing the display mode of the guide image Gi, the user can intuitively recognize the inter-vehicle distance.
For example, the overlapping part display changing unit 35 is configured to change the color according to the inter-vehicle distance. The overlapped part display changing unit 35 changes the color tone of the entire guide image Gi stepwise or continuously in the order of green, orange, and red as the inter-vehicle distance becomes shorter. The operator can intuitively grasp the inter-vehicle distance by changing the display mode of the guidance image Gi.

6). Forward vehicle recognition unit 34
The forward vehicle recognition unit 34 is a functional unit that recognizes a forward vehicle, which is another vehicle that is traveling ahead of the host vehicle, based on a forward landscape image.
The forward vehicle recognition unit 34 is configured to perform an image recognition process such as edge detection on the forward landscape image to recognize the forward vehicle. As shown in FIG. 13, the forward vehicle recognition unit 34 is configured to determine a region Ac that includes the forward vehicle in the forward landscape image as a rectangular region. Further, as shown in FIG. 14, the forward vehicle recognition unit 34 is configured to determine not only the area Ac of the vehicle ahead of the current travel lane but also the area Ac2 of the vehicle ahead of the adjacent travel lane. The forward vehicle recognition unit 34 may be configured to recognize an oncoming vehicle or a stopped vehicle traveling in the oncoming lane as a forward vehicle. Thus, the forward vehicle recognition unit 34 may be configured to recognize all other vehicles captured in the forward landscape image as forward vehicles.

7). Inter-vehicle distance determination unit 37
The inter-vehicle distance determination unit 37 is a functional unit that determines the inter-vehicle distance between the host vehicle and the preceding vehicle.
In the present embodiment, the inter-vehicle distance determination unit 37 modifies Equation (5) based on the position Cd of the lower end portion of the preceding vehicle and the length Hd between the front edge center point Pc and the vanishing point Pd. The inter-vehicle distance Cz can be determined using a calculation formula as shown in the following formula.
Cz = Hd / (Hd−Cd) × Fd (6)
Here, Cz is the inter-vehicle distance between the host vehicle and the preceding vehicle on the actual traveling road. As shown in FIG. 15, the position Cd of the lower end portion of the forward vehicle is the position of the lower end portion of the area Ac of the forward vehicle in the forward landscape image recognized by the forward vehicle recognition portion 34, and the front edge along the straight forward direction It is the length between the center point Pc of a part and the lower end part of a front vehicle. Hd is a length between the front edge center point Pc and the vanishing point Pd in the front landscape image. Fd is the focal length of the camera 44.

  The inter-vehicle distance determination unit 37 may be configured to determine the inter-vehicle distance between the host vehicle and the preceding vehicle using a detection signal of a radio wave or optical radar. Radar radio waves or light is emitted toward the front of the vehicle. The inter-vehicle distance determination unit 37 may be configured to determine the inter-vehicle distance based on a captured image of a stereo camera.

8). Flowchart The processing procedure (guidance display method and guidance display program) of the guidance display system 1 will be described with reference to the flowchart shown in FIG.
In step # 01, a guide route acquisition process (guide route acquisition step) for acquiring the guide route of the host vehicle is executed. In the present embodiment, the guidance route searched by the guidance route search unit 40 is acquired.
In step # 02, a landscape image acquisition process (landscape image acquisition process step) for acquiring a forward landscape image that is an image of a landscape in front of the host vehicle is executed.
In step # 03, a forward vehicle recognition process (a forward vehicle recognition step) for recognizing a forward vehicle, which is another vehicle traveling in front of the host vehicle, based on the forward landscape image is executed.
In step # 04, a guidance image generation process (guidance image generation step) for generating a guidance image for guiding the host vehicle is executed. At this time, the overlapping part display changing process by the overlapping part display changing part 35 and the distance corresponding display changing process by the distance corresponding display changing part 36 are executed.
In step # 05, a display process (display step) is performed in which the guidance image is displayed on the display device so as to overlap the front landscape image or the landscape in front of the host vehicle.

[Other Embodiments]
Finally, other embodiments of the present invention will be described. Note that the configuration of each embodiment described below is not limited to being applied independently, and can be applied in combination with the configuration of other embodiments as long as no contradiction arises.

(1) In the above embodiment, the information terminal device 2 in which the guidance display system 1 is incorporated, the guidance route search unit 40, the own vehicle position acquisition unit 41, the location information detection device 42, the map database 43, the camera 44, and the display The case where the device 45 and the inter-vehicle distance determination unit 37 are provided has been described as an example. However, the embodiment of the present invention is not limited to this. That is, part or all of the guidance route search unit 40, the own vehicle position acquisition unit 41, the position information detection device 42, the map database 43, the camera 44, the display device 45, and the inter-vehicle distance determination unit 37 are the same as those of the information terminal device 2. It may be provided outside and configured to be able to perform data communication with the information terminal device 2 through data communication such as wireless communication or wired communication.

(2) In the above-described embodiment, the case where the guide image generation unit 32 is configured to change the display mode of the guide image according to the inter-vehicle distance has been described as an example. However, the embodiment of the present invention is not limited to this. That is, the guide image generation unit 32 may be configured not to change the display mode of the guide image according to the inter-vehicle distance.

  The present invention can be suitably used for a guidance display system that displays a guidance image for guiding a vehicle.

1: Guidance display system 2: Information terminal device 30: Guidance route acquisition unit 31: Landscape image acquisition unit 32: Guidance image generation unit 33: Display unit 34: Forward vehicle recognition unit 35: Overlapping portion display change unit 36: Distance correspondence display Change unit 37: Inter-vehicle distance determination unit 40: Guidance route search unit 41: Own vehicle position acquisition unit 42: position information detection device 43: map database 44: camera 45: display device Ac: front vehicle area Ano: non-overlapping area Ao : Overlapping region Cz: Inter-vehicle distance Fd: Focal length Gi: Guide image Pc: Front edge center point Pd: Vanishing point Pf: Focus position Td: Right / left turn position Tz: Distance to right / left turn position

Claims (8)

A guidance display system for displaying a guidance image for guiding a vehicle,
A guidance route acquisition unit that acquires the guidance route of the host vehicle;
A landscape image acquisition unit that acquires a forward landscape image that is an image of a landscape in front of the host vehicle;
A forward vehicle recognition unit for recognizing a forward vehicle that is another vehicle traveling in front of the host vehicle based on the forward landscape image;
A guidance image generation unit that generates the guidance image for guiding the host vehicle;
A display unit that displays the guidance image on a display device so as to overlap the front scenery image or the scenery in front of the host vehicle,
The guidance image generation unit is a guidance display system in which a display mode is different between an overlapping area that overlaps the preceding vehicle in the guidance image and a non-overlapping area that does not overlap the preceding vehicle in the guidance image.   The guidance display system according to claim 1, wherein the guidance image generation unit changes a display mode of the guidance image according to an inter-vehicle distance between the host vehicle and the preceding vehicle.   The guidance display system according to claim 1 or 2, wherein the guidance image generation unit changes at least one of color and transparency between the overlapping region and the non-overlapping region.   The guidance display system according to any one of claims 1 to 3, wherein the guidance image generation unit makes the transparency of the guidance image in the overlapping region higher than the transparency of the guidance image in the non-overlapping region.   The guide image generation unit sets the overlapping area as an image formed with a hollow outline, and sets the non-overlapping area as an image or a pattern in which the area surrounded by the outline is filled. The guidance display system according to any one of claims 1 to 4.   The guidance display system according to any one of claims 1 to 5, wherein the display unit arranges the guidance image so as to overlap with a road included in the front landscape image or a landscape ahead of the host vehicle. . A guidance display method for displaying a guidance image for guiding a vehicle,
Arithmetic processing unit
A guidance route obtaining step for obtaining a guidance route of the host vehicle;
A landscape image acquisition step of acquiring a front landscape image that is an image of a landscape in front of the host vehicle;
A forward vehicle recognition step of recognizing a forward vehicle that is another vehicle traveling in front of the host vehicle based on the forward landscape image;
A guidance image generating step for generating the guidance image for guiding the host vehicle;
A display step of displaying the guidance image on a display device so as to overlap the front landscape image or the landscape in front of the host vehicle; and
In the guide image generation step, a guide display method in which a display mode is different between an overlapping region that overlaps the preceding vehicle in the guide image and a non-overlapping region that does not overlap the preceding vehicle in the guide image. A guidance display program for causing a computer to execute processing for displaying a guidance image for guiding a vehicle,
A guidance route obtaining step for obtaining a guidance route of the host vehicle;
A landscape image acquisition step of acquiring a front landscape image that is an image of a landscape in front of the host vehicle;
A forward vehicle recognition step of recognizing a forward vehicle that is another vehicle traveling in front of the host vehicle based on the forward landscape image;
A guidance image generating step for generating the guidance image for guiding the host vehicle;
A display step of displaying the guidance image on the display device so as to overlap with the front landscape image or the landscape in front of the host vehicle;
To the computer,
In the guide image generation step, a guide display program for differentiating the display mode between an overlapping region that overlaps the preceding vehicle in the guide image and a non-overlapping region that does not overlap the preceding vehicle in the guide image.

Images